Of course, this is a rather different kind of physical object from the
kind of objects we are used to. It is really made of spacetime
curvature than matter/energy (or more properly, the traditional
matter/energy parts have been hidden inside and may have become
something completely different - it doesn't matter). But it can be
pushed around and likely used, so it is really an object. The
spacetime as a rubbersheet analogy is good to a point, but then it
starts to fail.